For the reaction \( 2N_2O_5 \rightarrow 4NO_2 + O_2 \), rate and rate constant are \( 1.02 \times 10^{-4} \, \text{mol} \, \text{lit}^{-1} \, \text{s}^{-1} \) and \( 3.4 \times 10^{-5} \, \text{s}^{-1} \), respectively when the concentration of \( N_2O_5 \) at that time will be: